import React from "react";
function App() {
  return (
    <div className="App">
      <header className="App-header">
        <h1>
          hello
          <h2>world</h2>
          <h3>你好 世界</h3>
        </h1>
        <hr />
        <code>我叫长青</code>
        <hr />
        <a
          className="App-link"
          href="https://reactjs.org"
          target="_blank"
          rel="noopener noreferrer">
          Learn React
        </a>
      </header>
    </div>
  );
}

export default App;
